Mobile crane



Nov. 26, 1963 s. G. KNIGHT 3,112,035

MOBILE CRANE Filed July 28, 1961 4 Sheets-Sheet 1 INVENTOR SIDNEY 6. KNIGHT BY W,

ATTORNEYS S. G. KNIGHT MOBILE CRANE Nov. 26, 1963 4 Sheets-Sheet 2 Filed July 28, 1961 BYW/ ATTORNEYS Nov. 26, 1963 Filed July 28, 1961 S. G. KNIGHT MOBILE CRANE 4 SheetSSheet 3 INVENT OR "5 g SIDNEY a. KNIGHT 2- f BYFM,%%QMMW ATTORNEYS S. G. KNIGHT Nov. 26, 1963 MOBILE CRANE 4 Sheets-Sheet 4 Filed July 28, 1961 INVENTOR SIDNEY 6. KNIGHT BYW,

ATTORNEYS United States Patent 3,112,035 MOBILE CRANE Sidney G. Knight, Schofield, Wis., assignor to Drott Manufacturing Corporation, Milwaukee, Wis., a corporation of Wisconsin Filed July 28, 1961, Ser. No. 127,560 Claims. (ill. 21255) This invention relates to a crane assembly supported on a vehicle, and generally is comprised of a rotating mast assembly supporting a telescoping boom construction.

One objective of this invention is to provide a threesectioned telescopic boom in which a hydraulic cylinder is fixedly secured in the middle section of the boom, and the piston rod thereof attached to a section of the boom fixedly secured to the mast assembly.

Another objective of this invention is to provide a multi-sectioned boom of the type described wherein a mid-section houses a power actuated cylinder, the piston rod of which is secured to an end section thereof, and said cylinder is provided with means to extend and retract a load-carrying section of said boom at a correspondingly greater speed than the motion imparted to the cylinder carrying section.

A further objective of the invention is to provide a boom assembly of the type described wherein a hydraulically operated winch assembly is mounted forwardly of the mast and toward the lifting end of the boom assembly providing increased access for maintenance, better weight distribution, and a more balanced appearance for the machine in its entirety.

A still further objective of the invention is to provide a three-sectioned telescoping boom having novel bearing supports for increasing the life of the boom and increasing its ruggedness while not materially affecting its weight.

Another important objective of the invention is the provision of a unique mounting means for securing the boom construction to the mast assembly and for transmitting the power for vertical pivoting movement.

A still further important objective of the invention is the provision of a novel cable arrangement for use with a centrally mounted hydraulic cylinder to extend and retract the telescoping boom by variations in pressure on either side of a piston head at a stationary fixed distance from the mast and connecting the cables to the load-carrying section to move this last-mentioned section an amount greater than that imparted to the cylinder.

The invention further provides, as an advantage of the interior cylinder, that the cylinder carrying section moves independently of the cable system, and the cable lengths are thereby kept to a minimum.

Another important objective of the invention is to provide a safety guide for the winch cable which will insure that no portion of a broken cable will be of a sufiicient length to strike an operator on the vehicle.

These and other important objectives and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating a presently preferred embodiment thereof, and wherein:

FIG. 1 is a perspective View of the invention mounted on a wheeled vehicle;

FIG. 2 is an elevational view of the mast assembly with portions broken away;

FIG. 3 is a perspective View of the vertical lift and support mechanism with portions broken away;

FIG. 4 is an elevational view of the boom assembly showing the interior thereof;

FIG. 5 is a partial plan view of the boom assembly with portions of the housing broken away;

FIG. 6 is a sectional view along the line 6-6 of FIG. 4; and

3,1 12,035 Patented Nov. 26, 1963 FIGS. 7 and 8 are diagrammatic showings of boom movement and cable operation.

Referring now to 'FIG. 1, the numeral 10 indicates a mechanism embodying the invention. The invention is comprised basically of a boom assembly 12, a winch hoist assembly 15, and a mast assembly 16. The mast is supported substantially in the center of a wheeled or track laying vehicle 18. The mast assembly is supported on the platform 20 of the vehicle 18 by way of a non-rotatable heavy duty annular mounting plate 22. A nonrotatable tubular standard 24 is affixed to the plate and extends vertically upward therefrom. The mast itself is indicated by the numeral 26, and is rotatably received in standard 24 by way of upper and lower annular roller bearings 28 and 30. The mast support permits rotary motion in the mast and is capable of withstanding the boom loads. The upper portion of the mast is strengthened as indicated by the thickened portion 27. Depending from the lower end of mast 26 is a connecting member 29 comprised of an upright tubular sleeve 31 and an outwardly extending annular flange 33 near its lower end. The flange is bevel-geared about its upper surface as indicated by the numeral 34. The mast is rotated through the use of a shaft driven bevel gear 32 meshing with the mating annular beveled surface 34. The bevel 32 is driven, preferably through hydraulic system, from the vehicle engine, the speed and direction of which are operator controlled.

Rotatably received within the member 29' is a conventional multi-circuit hydraulic swivel 36. This swivel receives and exhausts hydraulic pressure via conduits 38 and 40. The swivel is equipped with a plurality of output conduits 42 which extend the length of the mast. The equipment operated by these outputs is described in greater detail hereinafter. The operative hydraulic connections to the equipment, such as swivel 36, are known to the art, and are not meant to be within the scope of this invention.

Housed within mast 26 is a hydraulic cylinder 44. The cylinder rotates Wit-h the mast 26. Lateral movement is prevented by retaining bolts 45. A piston rod 46 extends vertically from cylinder 44, and is terminated at its upper end by a bearing yoke 48. The bearing yoke receives a transversely horizontally disposed pivot pin 50.

The hydraulic clinder 44 is double acting and receives its power from any pair of tubes 42 through conventional valve connections under the control of the operator.

Extending angularly outwardly and upwardly from the upper portion of mast 26 is a pivot extension 52 terminated by a journal 54 at its outer end.

The boom assembly 12 is comprised basically of three telescopic sections 56, 58, and 60. Section 56 has two downwardly extending plates 62 and 64 extending over, but spaced from, the upper portion 27 of mast 26. Near the rear of section 56, the plates 62 and 64 are respectively journalled at 66 and 67. These journals are aligned with the journal 54 of extension 52, and are operatively connected by a pivot pin 70. Pin 70 provides boom 12 with its vertical pivot point.

Plates 62 and 64 are also journalled along their lower ends at 72 and 74. A pair of pins 76 and 78 are respectively secured in journals 72 and 74, and are of sufiicient length to pivotall'y receive a pair of linkage arms 80 and 82. At their other ends, arms 80 and 82 are secured about pin 50 of yoke 48. The main weight of the boom assembly is transferred to cylinder 44 via the linkage arms 80 and 82.

It can be seen that upon a straight vertical movement of piston rod 46 the boom assembly 12 will pivot about the rcarwardly disposed horizontal pin 70' and the vertical angle assumed by the boom wil be controlled by 3 the height of yoke 48. The horizontal direction of the boom, of course, is determined by the amount of slew imparted via bevel 32.

The linkage arms 80 and 82 are therefore pivotally connected to the boom assembly at one end and to the mast assembly at their other ends. As yoke 48 is vertically raised, linkage arms 80 and 82 account for the arcuate movement of any fixed point on the boom assembly.

Referring now to FIGS. 1 and 4, it is seen that inter-.

mediate section 58 is telescopically received in base section 56, and the end section 69 is telescopically received in section 58. Base section 56 is equipped with a back plate 84 at that end disposed near the pivot point 70. Fixedly secured within midsection 58, and extending substantially throughout its length, is a double acting hydraulic cylinder 86. Section 58 is open at its forward end to receive section 60 and has a back plate 59 at its inner end to which the base of cylinder 86 is welded or otherwise secured at 61. Extending rearwardly of cylinder 86, through an opening in back plate 59, is a piston rod 88 which is secured to the base plate 34 of base section 56. Mounted on the forward end of cylinder 86 is a sheave 9t), and mounted to base plate 59 is a second sheave 92. The sheaves, therefore, as far as relative movement with cylinder 86 is concerned are stationary. Sheave 90 is mounted on an angularly disposed slide plate 91 which is slidably received in end section 60. Slide plate 91 is welded to the forward end of cylinder 86. Bearing surfaces 93 and 93' are provided to engage the slide plate. Note (FIG. 6) that sheave 90 and the slide plate are canted 45 to the rectangular cross-section of section 60 permitting the use of a maximum size sheave.

A first cable 94 has one end aflixed to base plate 84 by way of adjustable nut 96. The cable 94 extends forwardly to sheave 90 through an aperture in base plate 59, surrounds the sheave, and returns rearwardly to point 98 at the rear of section 60 where it is afiixed. Therefore, an outward movement of cylinder 86 causes sheave 90 to move outwardly, which in turn causes section 6%) to extend with respect to section 58.

One end of a second cable 190 is secured to the outer end of section 58 by way of adjustable nut 102. Cable 100 extends rear-wardly, around sheave 92, and forwardly to the rear of section 60 where it is secured at 194. Appropriate apertures in back 59 are provided for this purpose.

Therefore, as section 58 is withdrawn into section 56 sheave 92 will move rearwardly causing section 60 to retract with respect to section 58 because of cable 100. Adjustable nuts 96 and 102 are provided merely to adjust the tension in the cables for efiicient operation.

Attached to the exterior top rear section 58 are a pair of guide bearing members 106 and 108. These members bear against the upper inner surface of section 56 and maintain the member 58 vertically aligned therein as it is extended and retracted.

Referring to FIG. 5, a pair of vertical roller guides 1G9 and 169 are disposed along the sides of section 56 to engage section 58 and cooperate with the aligning functions of members 136 and 108. Affixed to the inner bottom and forward surface of section 56 is a bearing plate 110, and affixed to the outer bottom and rear end of section 58 are bearing plates 112.

Section 60 is equipped at its rearward upper end with bearing plate 114, and is supported at its forward end on bearing plate 116 which is affixed to the forward bottom surface of section 58.

The bearing surfaces described will wear, of course, after a period of use. Consequently, to compensate for any uneven wearing, base plate 84 is equipped with a longitudinal vertically disposed slot 118 to receive the rearward end of piston rod 88. A block 120 affixed to the piston rod interiorly of plate 84 and a plurality of roller pins 122 secured. exteriorly thereof permit a slight vertical movement in the rod when necessary. This slight movement will prevent a binding of the rod in the cylinder in the event of wear in the horizontally disposed bearing surfaces.

The winch assembly 15 is received between the angle formed by the leading edges of plates 62 and 64, and the bottom of section 56. The winch is driven by hydraulic motor 126 which is secured to plate 62. Motor 26 is fed by fluid conduits 127 as seen in FIG. 1. Pressure in conduits 127 is, of course, under the operator controlled valves in any conventional manner. A winch cable 128 extends forwardly of the winch assembly through a longitudinal guide member 130. Depending from the outer end of section 58 is a guide safety loop 132 aligned with the guide 130. Section 60 is equipped at its outer end with a downturned section 134 in which a sheave 136 is mounted.

Cable 128 extends through guide loop 132 to engagement with sheave 136. The cable supports a hoist block sheave 140 and its outer end is secured to the outer end of section 60 at 142. Conventional automatic take-up and pay-out controls for hoist cable 128 may be used in cooperation with the boom extension means.

The mounting of winch 124 forwardly of the mast reduces the length of cable required for all operations. Safety guide members and 132 prevent any length of cable 123 from striking an operator, no matter where the cable is broken.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and efficient embodiments of my invention, it should be well understood that -I do not wish to be limited thereto, as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

I claim:

1. A crane assembly comprising in combination, a vertical mast, means to rotate said mast about its vertical axis, a multi-sectional boom, a first section of said boom mounted on said mast, a second section telescopically received in said first section, and a third section telescopically received in said second section, a hydraulic cylinder fixedly secured in said second section, a piston head in said cylinder, a piston rod extending from said head and secured to said first section, a first sheave at one end of said cylinder and a second sheave at a second end ofsaid cylinder, a first cable affixed to said first section, engaging said first sheave, and attached to said third section, a second cable attached to said first section, engaging said second sheave and attached to said third section, and means to move said cylinder with respect to said piston head.

2. A crane assembly comprising in combination, a vertical mast, means to rotate said mast about its vertical.

axis, a multi-sectional boom, a first section of said boom mounted over said mast and having a portion thereof extending rearwardly and a portion thereof extending forwardly, a second section telescopically received in the forward end of said first section, and a third section telescopically received in the forward end of said second section, a hydraulic cylinder having a first end fixedly secured to said second section and a second end slidably received in said third section, a piston head in said cylinder, a piston rod extending from said head and secured to the rear of said first section, a first sheave at the rear end of said cylinder and a second sheave at the forward end of said cylinder, a first cable affixed to said first section,.

engaging said first sheave, and attached to said third section, a second cable attached to said first section, engaging said second sheave and attached to said third section,

and means to move said cylinder with respect to said pis-- ton head.

3. A crane assembly comprising in combination, a vertical mast, means to rotate said mast about its vertical axis, a multi-sectional boom, a first section of said boom mounted on said mast, a second section telescopically received in said first section, and a third section telescopically received in said second section, a hydraulic cylinder fixedly secured in said second section, a piston head in said cylinder, a piston rod extending from said head and secured to said first section, a first sheave at one end of said cylinder and a second sheave at a second end of said cylinder, a first cable aflixed to said first section, engaging said first sheave, and attached to said third section, a second cable attached to said first section, engaging said second sheave and attached to said third section, and means to move said piston head with respect to said cylinder, a pair of plates depending from said first section and receiving said mast therebetween, an arm extending out wardly from said mast and pivotally connected at its outer end to said plates, a vertically movable member in said mast, a pair of linkage arms pivotally connected to said member and said plates whereby a straight line movement in said member causes said boom to pivot about said outer end of said arm.

4. A crane assembly comprising a support, a mast, means rotatably mounting said mast on said support, an upwardly and outwardly inclined arm extending rearwardly from said mast, a hydraulic cylinder housed in said mast and rotatable therewith, a piston rod extending upwardly from said cylinder, a telescopic boom having its rearward end pivotally secured to said arm and extending forwardly over said piston rod, a pivotal linkage arm between said rod and said boom, a first section of said boom mounted on said mast, a second section telescopically received in said first section, and a third section telescopically received in said second section, a second hydraulic cylinder fixedly secured in said second section, a piston head in said second cylinder, a second piston rod extending from said head and secured to said first section, a first sheave at one end of said cylinder and a second sheave at a second end of said cylinder, a first cable atfixed to said first section, engaging said first sheave, and attached to said third section, a second cable attached to said first section, engaging said second sheave and attached to said third section, and means to move said piston head with respect to said cylinder. 1

5. A crane assembly comprising in combination, a vertical mas-t, a boom including three telescopically interfitting sections, a first of said three sect-ions being mounted on the mast, a second section telescopically interfitting with the first section, and a third section telescopically interfitting with the second section, a power motor connected to the first and second sections to move them telescopically relative to each other, a pair of guide sheaves mounted on the second section, a first cable secured at one end to the inner end of the first section and looped over one of the sheaves with its other end secured to the inner end of the third section, and a second cable secured at one end to the outer end of the first section and looped over the other sheave with its other end secured to the inner end of the third section.

References Cited in the file of this patent UNITED STATES PATENTS 2,668,625 Garland Feb. 9, 1954 2,684,159 Oldenkamp July 20, 1954 2,833,422 Ferwerda et al. May 6, 1958 2,895,622 Sundin July 21, 1959 2,911,111 Grove Nov. 3, 1959 3,029,954 Grant Apr. 17, 1962 

1. A CRANE ASSEMBLY COMPRISING IN COMBINATION, A VERTICAL MAST, MEANS TO ROTATE SAID MAST ABOUT ITS VERTICAL AXIS, A MULTI-SECTIONAL BOOM, A FIRST SECTION OF SAID BOOM MOUNTED ON SAID MAST, A SECOND SECTION TELESCOPICALLY RECEIVED IN SAID FIRST SECTION, AND A THIRD SECTION TELESCOPICALLY RECEIVED IN SAID SECOND SECTION, A HYDRAULIC CYLINDER FIXEDLY SECURED IN SAID SECOND SECTION, A PISTON HEAD IN SAID CYLINDER, A PISTON ROD EXTENDING FROM SAID HEAD AND SECURED TO SAID FIRST SECTION, A FIRST SHEAVE AT ONE END OF SAID CYLINDER AND A SECOND SHEAVE AT A SECOND END OF SAID CYLINDER, A FIRST CABLE AFFIXED TO SAID FIRST SECTION, ENGAGING SAID FIRST SHEAVE, AND ATTACHED TO SAID THIRD SECTION, A SECOND CABLE ATTACHED TO SAID FIRST SECTION, ENGAGING SAID SECOND SHEAVE AND ATTACHED TO SAID THIRD SECTION, AND MEANS TO MOVE SAID CYLINDER WITH RESPECT TO SAID PISTON HEAD. 